A flexible, distributed, pluggable model harness framework based on Kotlin/JVM. With minimal amount of UI code, you can build a whole harness with Alexandrite in days. Available in maven central already.
Alexandrite assistant is available here, serving as a BYOK (bring-your-own-key) agent gateway to multiple platforms (for now only telegram). Many features are already available, e.g. untrust taint mode, sandboxed runtime, permission modes and subagent workflows. Currently in alpha test, expect rough edges and breaking changes.
More about Alexandrite is yet to come in the future.